**Exhibit10.6**

ASSUMED ELIGIX, INCAMENDED AND RESTATEDMANAGEMENT EQUITY INCENTIVE PLAN

             Reference is hereby made to thatcertain Management Equity Incentive Plan of Eligix, Inc. (the “Company”)approved by the Board of Directors of the Company on May 25, 2000 (the“Management Incentive Plan”).  Thepurpose of the Management Incentive Plan is to provide the individuals listedon Schedule A hereto (the “Participants,” and each, a “Participant”)with an aggregate of 15% of the gross consideration received by the Company inthe event of a merger, reorganization, consolidation or similar businesstransaction (a “Merger”) involving the Company and another entity, includingfor this purpose BioTransplant Incorporated, a Delaware corporation (the“Successor Company”).

             The Management Incentive Plan ishereby amended and restated in its entirety as follows:

             The Participants shall be entitledto an aggregate of 15% of the consideration received by the Company in a Mergerinvolving the Company and a Successor Company.  In the event that any portion of the consideration consists ofstock of the Successor Company (“Stock Consideration”), each such Participant’sportion of the Stock Consideration shall be subject to the following vestingschedule:

             a.          331/3% shall vest 90 days subsequent to the closing of the Merger;             b.          another 33 1/3% shall vest 180 days subsequent to theclosing of the Merger;             c.          another 23 1/3% shall vest 270 days subsequent to theclosing of the Merger; and             d.          the final 10% shall vest 365 days subsequent to the closingof the Merger;

provided,however, that if such Participant is not offered employment with the SuccessorCompany or its affiliates other than the joint venture with Novartis, suchParticipant’s portion of the Stock Consideration will vest upon closing of theMerger; and further provided that if such Participant’s employment isterminated by the Successor Company without “Cause” or by the Participant for“good reason,” such Participant’s portion of the Stock Consideration will vestupon such termination.  If anyParticipant’s employment is terminated by the Successor Company for cause, orby the Participant without good reason, the Successor Company may, but is notrequired to, purchase any and all shares of such Participant’s portion of theStock Consideration that has not yet vested at a price of $.01 per share.  Such Participant’s portion of the StockConsideration will also be subject to any escrow arrangements applicable to theholders of the Company’s capital stock in connection with the Merger.

             The Stock Consideration will becomeimmediately vested in the event of (i) any consolidation or merger of theSuccessor Company with or into any other corporation, or any other corporatereorganization, in which the stockholders of the Successor Company immediatelyprior to such consolidation, merger or reorganization own less than 50% of thevoting power of the company succeeding the Successor Company immediately aftersuch consolidation, merger or reorganization; (ii) any transaction or series ofrelated transactions in which in excess of fifty percent (50%) of the SuccessorCompany’s voting power is transferred; (iii) a sale, lease or other dispositionof all or substantially all of the assets of the Successor Company; or (iv) anysale or transfer of all or substantially all of those assets held by theCompany prior to the Merger.
             For purposes of this ManagementIncentive Plan, “cause” shall mean (i) the willful (or grossly negligent) andrepeated neglect by the Participant of his or her reasonably assigned dutieswith the Successor Company; provided such neglect remains uncured for a periodof thirty (30) days after written notice describing the same is given to theParticipant; and further provided, that the Participant is afforded an opportunityto be heard on the matter by the Chief Executive Officer or the Board ofDirectors of the Successor Company; (ii) the Participant’s conviction of anyfelony or any other crime involving Successor Company funds, Successor Companyintellectual property or the theft of Successor Company funds, SuccessorCompany intellectual property or the theft of Successor Company property; (iii)the breach by the Participant of any non-competition, non-solicitation,confidentiality or comparable agreement with the Successor Company asdetermined by a court of competent jurisdiction; or (iv) the Participant’shabitual drunkenness, use of illegal substances or drugs or the habitual use,possession, distribution or being under the influence of alcohol or illegalsubstances or drugs in the workplace (the only exception is that theParticipant may consume alcohol reasonably and responsibly, if he or she sochooses, at legitimate business events and functions where alcohol is legallyavailable).

             For purposes of this ManagementIncentive Plan, “good reason” shall mean (i) any significant diminution,without the Participant’s prior written consent, in the Participant’s duties,responsibilities, power, title, or office; (ii) any material reduction in theParticipant’s compensation (including without limitation, salary, bonuses,options and benefits) or material change in the manner of the Participant’scompensation (including without limitation, the timing of any salary or bonuspayments) in effect on the date hereof or as the same may be increased duringthe Participant’s employment; (iii) any requirement by the Successor Company orany successor that the location at which the Participant is to perform theParticipant’s principal duties for the Successor Company or any successor beoutside a radius of fifty (50) miles from the location at which the Participanthad previously performed such duties immediately prior to the change oflocation; or (iv) any breach by the Successor Company of any material provisionof this Management Incentive Plan or any other agreement between the SuccessorCompany and the Participant.

             It is hereby acknowledged andagreed that all of the Participants are at-will employees, that nothing statedin this Management Incentive Plan alters such status.  Accordingly, each such Participant’s employment may be terminatedby the Company, the Successor Company or the Participant at any time for anyreason and no such Participant is guaranteed employment for any specific periodof time.

             This Management Incentive Planshall be assumed by the Successor Company in any Merger.

             This Amendment and Restatement ofthe Management Equity Incentive Plan shall become effective upon the Closing ofthe Merger.
 Adopted by the  Board of Directors  on December 8, 2000
BioTransplantIncorporatedBuilding 75, 3rd AvenueCharlestown Navy YardCharlestown, MA  02129Attn:    ElliotLebowitz             Chief Executive Officer

Ladiesand Gentlemen:

             In connection with the closing ofthe merger contemplated by the Agreement and Plan of Merger (the “MergerAgreement”) dated as of December 8, 2000 among BioTransplant Incorporated(“BTI”), Eligix, Inc. (“Eligix”) and the other parties thereto, certain membersof management of Eligix are to receive 990,000 shares of BTI Common Stockpursuant to the Eligix Management Equity Incentive Plan (the “Plan”), aspreviously adopted by Eligix on December 8, 2000.  In order to resolve any ambiguities in the operation of the Planresulting from (a) the resignation from Eligix of Cynthia Letizia and (b) DavidCook’s decision to join BTI as an employee for only a limited period of timefollowing the closing of the merger, each of which event has occurred followingthe date of the Merger Agreement, we have agreed that the Plan shall beimplemented in accordance with the provisions of the Plan, the Merger Agreementand the Escrow Agreement (as defined in the Merger Agreement), subject to thefollowing modifications:

             1.          Thepercentage of shares initially allocated to Cynthia Letizia shall bere-allocated among the remaining 11 initial Plan participants (the “InitialParticipants”) including, for this purpose, David Cook, on a weighted averagebasis in accordance with the initial percentage interests of the InitialParticipants.

             2.          Theshares representing David Cook’s percentage participation in the Plan aftergiving effect to the modifications set forth in paragraph 1 (102,414 shares,hereinafter the “Cook Shares”) shall be treated as follows:

                           (a)         first, David Cook’s percentage interestin the Plan shall be reduced to 34,135 shares in accordance with his offerletter with BTI (the “Offer Letter Shares”); and

                           (b)        second, the remaining Cook Shares (lessthe Offer Letter Shares) shall be distributed among the Initial Participants(excluding, for this purpose, David Cook) on a weighted average basis inaccordance with the percentage interests of the Initial  Participants after giving effect to themodifications in paragraph 1(as re-calculated, on a weighted average basis, toexclude David Cook), and among certain other employees of Eligix who shallbecome employees of BTI, in accordance with the Proceed Sharing Matrix attachedhereto (the “New Participants”).

             Giving effect to the foregoingmodifications, the allocation of percentages and shares for each of the InitialParticipants (including, for this purpose, David Cook) is as set forth on theProceed Sharing Matrix attached hereto.

             We have also agreed thateach of the New Participants, as a condition to his or her receipt of benefitsunder the Plan in accordance with the terms of this letter, shall execute anddeliver to BTI, within ten (10) business days following the date hereof, acounterpart signature page to the Escrow Agreement.

             Eligix represents and warrants toBTI that Cynthia Letizia is not a Plan participant or eligible to receive anyequity under the Plan.  Eligix furtheragrees that BTI may seek indemnification for any Damages (as defined in theMerger Agreement) for breach of this representation in accordance with the indemnificationprovisions of Article IV of the Merger Agreement and the provisions of theEscrow Agreement.

             If you are in agreement with theforegoing, please confirm this agreement by signing this document in the spaceindicated below.
  Very truly yours,     /s/ Walter C. Ogier    Walter C. Ogier  Chief Executive  Officer  Eligix, Inc.      Agreed and Accepted:     BioTransplant  Incorporated     /s/  Elliot Lebowitz    Elliot Lebowitz, Ph.D.  Chief Executive  Officer